Color stabilization of vinyl halide resins



the addition of a small proportion of aminoguanidine or salt thereof.

guanidine or a salt of amino-guanidine will en- The stabilizing agent may be incorporated by able the resin to resist the discoloration efiect any of several methods. It may be added to I for substantial periods of time.- 15 the solid resin and mixed therein by means of a The vinyl halide resins which may be stabilroll mill or other mixing machine adapted to percent of another polymerizable mono-olefinic means of any stirring device. If the polymers Patented Nov. 5, 1946 2,410,775

UNITED STATES PATENT OFFICE COLOR STABILIZATION OF VINYL HALIDE RESINS Fred W. Cox, Cuyahoga Falls, and James M. Wallace, Jr., Akron, Ohio, assignors to Wingfoot Corporation, Akron, Ohio, a corporation of Delaware 1 No Drawing. Application June 22, 1945,

. Serial No. 601,060

9 Claims. (01. 2s0 7s) 1 This invention relates to the stabilization of though any other salt of amino-guanidine may vinyl halide resins, and particularly the vinyl be used. The quantity of stabilizer used will halide resins which are polymers of at least 70 depend upon the conditions of heating to which percent of vinyl halide, including the polymers the vinyl resin is to be subjected. If only mild of 100 percent vinyl halide and the copolymers heating is encountered, small amounts or even of vinyl halides with other polymerizable monotraces of the agent will yield an improved prodolefimc compounds. uct. Although the incorporation of from 0.05 to .inyl halide resins generally will discolor when 10 percent by weight, based on the polymer conheated, for example at a temperature of 100 tent of the resin, will produce useful composi- C. or higher, and especially in the presence of 10 tions, generally the best results are obtained iron or iron salts. It has been discovered that from the use of from 0.5 to 5 percent of the ized in accordance with this invention include the blend solid plastic materials. The ,mixing mapolyvinyl halides, made by the polymerization chine may be heated during the mixing operof any compound of the group consisting of ation to render the compositions more plastic. vinyl chloride, vinyl bromide, vinyl fluoride and Alternatively, the stabilizing agent may be disvinyl iodide without the presence of other polysolved in any suitable solvent and the solution merizable mono-olefinic compounds. The inventhen mixed with the resin. The vinyl halide tion is also useful in the prevention of discolorresin may be dissolved in a solvent, such as ation upon heating in copolymers of from 70 to ethylene dichloride, and the stabilizing agent 100 percent of a vinyl halide with from 0 to 30 added to the solution and dispersed therein by compound. Although any polymerizable monoor copolymers are prepared by polymerization in olefinic compound which is compatible with the an aqueous emulsion, the stabilizing agent may Vinyl halide in p y e c fo m, i. 8-, which forms be added and distributed through the polymer copolymers therewith, may be stabilized, the inprior to coagulation. Any other method which vention is particula ly Useful in t t a e t Of permits a uniform distribution of the stabilizing copolymers of monomeric mixtures of vinyl halide agent throughout the polymer may be used. and up to 0 percent of Vi yl acetate, vi ylidene The stabilized resins may be used in theprepachloride, yrene, the alkyl fumarates, e alkyl ration of cast films or in the fabrication of maleates. e a y chloromaleates, the alkyl molded or extruded shapes, which uses are well hl r fuma a ath a y a ry at or t alp a known to the art. The stabilized vinyl halide substitut d al yl acrylates. The copo e s resins are particularly useful in the preparation which are of particular i p t a those of of transparent or light colored articles in which 70 to 98 percent of vinyl halide and from 2 to 30 discoloration upon heating is undesirable. p e t o s id ot e fi c o A Further details of the invention are set forth pr fe red c ass of copo m ar those of 80 to 95 with respect to the following specific examples. percent of vinyl halide and from 5 to 20 percent Exam le 1 of the other monomer. p a

The stabilization against discoloration upon Each of three 10 gram samples of a copolymer of heating is efiected by the incorporation of amino- 90 percent vinyl chloride and 10 percent diethyl guanidine or any salt of amino-guanidine. For fumarate were milled with 2 ml. of dibutyl sebaobvious economic reasons the most useful salts cate. Two of these samples were blended'respecof amino-guanidine are those made by the retively with 0.2 gram of amino-guanidine sulfate action of amino-guanidine with inexpensive readand with 0.2 gram of guanidine sulfate. The ily available acids. Thus, the most useful salts third sample wasused as a control for the purare the hydrochloride of amino-guanidine, the pose ofcomparison. The copolymer samples were bicarbonate of amino-guanidine, amino-guanimilled separately on a laboratory-size chromiumdine sulfate, amino-guanidine nitrate, aminoplated roll mill for 5 minutes at 140 F. and then guanidine acetate, amino-guanidine carbonate, for 5 minutes at 212 F. The copolymers were and the hydrosulfate of amino-guanidine, alrolled into sheets 1 mm. in thickness and Spegimens were cut therefrom for heat stability tests. The specimens were introduced into an oven heated at 135 C. and every half hour for 4 hours one of each type was withdrawn. It was found that the copolymer containing amino-guanidine sulfate was stabilized to the efiect of the elevated temperature, while the copolymer containing guanidine sulfate and the control specimen containing no modifying agent were discolored to about the same extent.

Example 2 Using the procedure described in Example 1 i the same copolymer was blended with 2 percent of amino-guanidine bicarbonate and another sample with guanidine carbonate. The effect of the addition of these modifying agents upon the heat stability of the copolymer was determined in the manner described in Example 1. After one hour of heating at 135 C. the specimen containing guanidine carbonate was discolored even more than the control specimen, containin no modifying agent, while the specimen containing 'mono-olefinic compound, said resin containing from 0.05 to 10 percent by weight based on the polymer content, of a compound of the group consisting of amino-guanidine and salts of aminoguanidine.

2. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of '10 to 98 percent of vinyl chloride and 2 to 30 percent of diethyl fumarate, said resin containing from 0.05 to 10 percent by weight based on the polymer content, of amino-guanidine.

3. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of to 98 percent of vinyl chloride and 2 to 30 percent of diethyl fumarate, said resin containing from 0.05120 10 percent by weight based on the polymer content, of a salt of amino-guanidine.

4. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of to percent of vinyl chloride and 5 to 20 percent of diethyl fumarate, said resin containing from 0.05 to 10 percent by weight based on the polymer content, of amino-guanidine.

5. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of 80 to 95 percent of vinyl chloride and 5 to 20 percent of diethyl fumarate, said resin containing from 0.05 to 10 percent by weight based on the polymer content, of a salt of aminoguanidine.

6. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of 70 to 98 percent of vinyl chloride and 2 to 30 percent of diethyl fumarate, said resin containing from 0.5 to 5 percent by weight based on the polymer content, of amino-guanidine.

7. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of '70 to 98 percent of vinyl chloride and 2 to 30 percent of diethyl fumarate, said resin containing from 0.5 to 5 percent by weight based on the polymer content, of a salt of aminoguanidine.

8. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of 80 to 95 percent of vinyl chloride and 5 to 20 percent of diethyl fumarate, said resin containing from 0.5 to 5 percent by weight based on the polymer content, of amino-guanidine.

9. A vinyl chloride resin capable of resisting discoloration upon heating which comprises a copolymer of 80 to 95 percent of vinyl chloride and 5 to 20 percent of diethyl fumarate, said resin containing from 0.5 to 5 percent by weight based on the polymer content, of a salt of aminoguanidine.

FRED W. COX. JAMES M. WALLACE, JR. 

